What force is needed to keeps 20kg box moving at a constant velocity when the mk is 0.3021 and the force is applied level to the ground

59.2 N

Explanation:

According to Newton's second law, the resultant of the forces acting on the box must be equal to the product between the box's mass and its acceleration:

However, the box is moving at constant velocity, so its acceleration is zero:

a = 0

Therefore, the net force along the direction of motion (parallel to the surface) must be zero.

We have two forces acting along the direction parallel to the ground:

- The applied force, F

- The frictional force, , in the opposite direction, with being the coefficient of friction, m = 20 kg the mass of the box and g = 9.8 m/s^2

Therefore, the equation of motion becomes:

And solving for F, we find:

conservation of mass

mass before something happens = mass afterwards

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle